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kdump: clear and EOI IPI for kexec CPU

PATCH In review Haren Myneni 2 participants 2 messages Mar 23, 2006 – Mar 27, 2006 PowerPC

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PATCH 1/1 kdump: clear and EOI IPI for kexec CPU

Paul, Sorry, Please ignore the previous patch since it has one tab/space issue. Tested this one and kdump-dma-fault-fix.patch on P5, P4 (non-lpar), JS21 and JS20.

Thanks
Haren

Some times, the kexec CPU is not reponding to an IPI during kdump boot. It is causing the system in xmon. Noticed on power-4 (non-lpar). This patch clears and EOI IPI for kexec CPU as well before the kdump boot started.

arch/powerpc/platforms/pseries/xics.c renamed from arch/powerpc/platforms/pseries/xics.c.orig +15 -10
@@ -641,22 +641,27 @@ void xics_teardown_cpu(int secondary)
 	iosync();
 
 	/*
+	 * Clear IPI
+	 */
+	ops->qirr_info(cpu, 0xff);
+	/*
+	 * we need to EOI the IPI if we got here from kexec down IPI
+	 *
+	 * probably need to check all the other interrupts too
+	 * should we be flagging idle loop instead?
+	 * or creating some task to be scheduled?
+	 */
+	ops->xirr_info_set(cpu, XICS_IPI);
+
+	/*
 	 * Some machines need to have at least one cpu in the GIQ,
 	 * so leave the master cpu in the group.
 	 */
-	if (secondary) {
-		/*
-		 * we need to EOI the IPI if we got here from kexec down IPI
-		 *
-		 * probably need to check all the other interrupts too
-		 * should we be flagging idle loop instead?
-		 * or creating some task to be scheduled?
-		 */
-		ops->xirr_info_set(cpu, XICS_IPI);
+	if (secondary) 
 		rtas_set_indicator(GLOBAL_INTERRUPT_QUEUE,
 			(1UL << interrupt_server_size) - 1 -
 			default_distrib_server, 0);
-	}
+	
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
#1 lore raw
Quoted 11 lines · Haren Myneni

Paul, Sorry, Please ignore the previous patch since it has one tab/space issue. Tested this one and kdump-dma-fault-fix.patch on P5, P4 (non-lpar), JS21 and JS20.

Thanks
Haren

Some times, the kexec CPU is not reponding to an IPI during kdump boot. It is causing the system in xmon. Noticed on power-4 (non-lpar). This patch clears and EOI IPI for kexec CPU as well before the kdump boot started.

Sorry, that commit message is quite opaque to me. Could you explain in more detail what the problem is and how this fixes it?

Thanks,
Paul.